A four-month old female dog, an Epagneul Breton, was taken to the out-patients dispensary of the Small Animals Clinic with the Belgrade School of Veterinary Medicine. The dog breathed heavily, coughed occasionally and regurgitated undigested food from esophagus. These symptoms were more obvious after intake of solid pelleted food. X-ray test result: the special neck and thorax x-ray showed round, baggy shadow of barium mush the size of lemon. Endoscopy test result: The tip of the endoscope could not pass through this dilation towards cardia due to severe esophageal stricture. We decided to perform the surgery: after the preparation the operative field, thoracotomy was done in the area of the fourth intercostal space on the left side. Esophagus diverticulum was noted, and then incision of esophagus carried out followed by preparation of esophagus at the stricture, insulation of lig. arteriosum and its ligating. The surgery ended in routine procedure of closing the chest cavity and placing a thoracic drain. The endoscopic finding in the course of the surgery: The endoscope tip passed through to cardia and entered the stomach rather easily. The x-ray test result ten days after the surgery: still shows a contrast path, immediately in front of the heart shadow, the size of a plum. X-ray test result 30 days after the surgery: diverticulum filled with contrast, anterior to the heart shadow, is still noticeable. The contrast meal is passing posterior towards the stomach.